The prevalence of congestive heart failure in the United States is nearly 5 million patients, with more than 500,000 new cases diagnosed per year. Of these patients, approximately 400,000 have a life expectancy of less than one year, and 200,000 die each year despite maximal medical therapy. To address the need for mechanical circulatory support in these patients, various left ventricular assist systems have been developed. Yet broad utilization of these devices has been limited by their size and cost. Our goal is to create a truly affordable left ventricular assist device, capable of meeting the needs of a broad range of patients with severe heart failure. The focus of this project will be to develop a miniature, low-cost, extracorporeal centrifugal left ventricular assist device, for use as a bridge-to-decision for durations ranging from days to months. Accordingly, the device will be designed to function as a bridge to recovery, transplant or an implantable device for patients in severe cardiac failure. The specific design will feature a novel magnetically levitated configuration, whose key features allow rapid acceleration and deceleration in response to prescribed motor input power cycles. The major advantages of the current design are its small and relatively simple extracorporeal design, its ability to efficiently regulate cardiac output over a large range of flow conditions, and its ease of production This program's overall goal will be to develop and optimize the design and construction of the magnetically levitated, centrifugal pump, and ascertain its physiological performance in vitro and in vivo. The specific aims of this proposal are to 1) Design and fabricate a long-term blood pump and pump controller. 2) Optimize pump design through a computational fluid dynamics model, which predicts system flow as a function of pump attributes. 3) Design and fabricate magnetically driven system controls and power supply integration. 4) Determine pressure-flow characteristics over a wide range of outputs. 5) Determine hemolysis levels over the expected range of cardiac outputs. 6) Perform preliminary in vitro endurance testing, 7) Conduct three acute in vivo experiments to demonstrate hemodynamic performance and biocompatibility. We believe that our technology, which provides effective left ventricular assistance with a small, disposable device, may provide needed benefits to the health of a broad range of patients, while not adding significantly to cost of caring for these patients. If we successfully meet the Phase I goals, we will propose in a Phase II program to refine the mechanical design with respect to manufacturing, optimize the ventricular assist control console (with appropriate safety and alarm systems), and expand the in vivo data to include longer-term animal experiments. This would provide a database to support the use of our device for long-term left ventricular support in clinical trials.